Here's the story. New TBI engine (350) with vortec heads requiring the GMPP TBI vortec manifold, and a freshly rebuilt transmission (700R4). The combo has 1200 miles on it, and I noticed from my datalogs that the transmission was slipping.

The transmission shifted nice and firm, and at the right time, so the only problem was when I jump on it.

I measured, and it looked like the bracket that holds the TV cable sat about a half inch too far forward. I welded some tabs on it to set it in the right position, and now it slips worse and shifts too soon. I adjusted the TV cable properly, and as designed, the cable will not pull out any further after WOT. If I "adjust" the cable, (further towards the rear) it shifts better, but it won't allow the throttle to go wide open.

My 1200 mile transmission now needs another $1600 rebuild and $300 torque converter. I doubt it's the builders fault because of this TV cable problem I've found, so there's no warranty since I installed it.

Any suggestions on what I can do to fix the TV problem?

 

Read this post. There's a spring you can buy really cheap that helps improve the shift points while still retaining WOT. https://www.thirdgen.org/forums/tran...=sonnax+spring There's a good chance it'll help cure your problem.

 

That looks like something I'd try if the cable protruding from the clips was longer. Installing a spring will just make it "shorter", though I see how it would work.

I see on the 700raptor.com site that they sell a longer cable, so that may allow me to use the spring.

 

all the spring is made to do is help correct the line pressure and shift points after a gear swap, like mine from 2:72 to 3:73, if there is a problem with the cable i dont think it will fix it.

 

I never changed gears, but with 100+ more horsepower, I imagine I'd have to adjust it some for more pressure.

 

I adjusted the TV cable properly, and as designed, the cable will not pull out any further after WOT. If I "adjust" the cable, (further towards the rear) it shifts better, but it won't allow the throttle to go wide open.


I wouldn't really consider it a "band-aid" fix if it takes care of the problem. With the spring installed, you can adjust your cable to where it shifts better, and still be able to have the throttle go wide open without the tv cable holding it back. To get that last bit of travel you need at WOT, the spring compresses, giving you about another 1/4" of travel.

 

I'm missing something. If the cable will only come out so far when you "adjust" it for better shifting, how is it that the spring creates more travel if the black clip is already at the end of it's rope (wire)?

Is there something that I should ask for when I have it rebuilt again? ie. different TV spring?

 

The way your tv cable is set up from the factory, once the cable is pulled out all the way, there's no travel left because the end of the cable is up against the black plastic piece that clips on the throttle linkage. When you install the spring, you're able to adjust the slider out further, and the spring takes up the additional slack in the cable, so your shift points will stay about the same, but when you floor it, the spring compresses, allowing that little bit of extra travel in the cable you need to be able to have the throttle wide open. It really makes more sense when you get the kit and put it on, then you can actually see what I'm trying to explain. GM should've put this spring on them in the first place. You can really fine tune the adjustment with it!

 

Alright, that makes sense. I think I'll order one up.